Actually, it took less than an hour. Most of the time (unless it's a particularly difficult mod), it only takes me about 20 minutes to do a normal mod. It's less if the photo is slightly out of focus (love that blur tool). The skin tones aren't really all that difficult to do, either. The key is using multiple layers for colors, and adjusting the source image by manipulating the brightness and contrast. Apply extra shadow as necessary with an additional layer on the "darken" channel. It took a lot of experimentation and practice (as you can see if you look at the progress of my work), but I think that method is about as efficient from a workflow perspective as it's going to get.